A global synthesis and meta-analysis of the environmental heterogeneity effects on the freshwater biodiversity

In this study, we aimed to synthesize the global knowledge about the
relationship between spatial Environmental Heterogeneity (EH) and
freshwater biodiversity (i.e., taxonomic and functional diversity, and
their respective α and β components). Through a systematic review, we
integrated results from 98 studies, published in 33 different countries,
about the role of spatial EH – biodiversity relationship in freshwater
ecosystems. Following the PRISMA-ecoevol criteria, we generated a dataset
with 276 observations of the effect of EH – biodiversity relationship. For
the meta-analysis, we extracted the effect size from 74 studies that
effectively tested the effect of EH over any metric of biodiversity.
Through this subset, we provided 242 individual effect sizes with their
respective variances and sample sizes.